EVCO S.p.A.
EVDRIVE04 | User manual ver. 1.0 | Code 144EPD4I104
Page 27 of 78
6.9
Debugging mode
The debugger feature is enabled when Pr02 = 2: the valve will move from a Debug minimum position (parameter Prd1)
to a Debug maximum position (parameter Prd2) with the step rate defined by Debug step rate (parameter Prd0).
Internally, the actuated step rate value is clamped to the maximum step rate of the selected valve.
6.10
Control algorithm
Setting the
Main control type
(parameter Pr01) selects the algorithm to enable:
-
Pr01 = 6: Superheat (SH) control algorithm
-
Pr01 = 8: Hot gas bypass control algorithm
6.10.1
Superheat control algorithm
The purpose of this control is to maintain the Superheat (SH) at its set-point value, in order to maximise the efficiency
of the system and ensure that the compressor is protected by entrance of liquid.
The SH is usually controlled by a PID.
After selecting the control algorithm, it is necessary to set the various regulation parameters:
•
SH set-point
(Pc01, Pp01)
•
LoSH set-point
(Pc02, Pp02)
•
HiSH set-point
(Pc03, Pp03)
•
LOP temperature
(Pc04, Pp04)
•
MOP temperature
(Pc05, Pp05)
•
PID proportional band (Pc13, Pp13)
•
PID integral time (Pc14, Pp14)
•
PID derivative time (Pc15, Pp15)
•
Start-up delay (Pc20, Pp20)
•
Start-up position (Pc21, Pp21)
•
Fast action (Pr12)
•
Neutral zone high threshold (Pr10)
•
Smart band zone threshold (Pr11)
•
SH filter time constant (Pr14)
•
Fast action threshold (Pr13)
SH parameters set selection
(SetP) supports selection of one of two different sets of regulation parameters. Each set
includes SH set-point, PID parameters, and LoSH, HiSH, MOP and LOP alarm set points, start up position and delay.
Example uses are: using set1 parameters for a chiller, set2 for a heat pump.
Position
100%
0%
t [s]
Step Rate = Prd0 step/s
Prd2%
Prd1%
